How the Silicon Metal to Be Made

The reaction is occurred in crucible (especially bottom) and the process as following:

Firstly, in view of high electricity current passing through electrode, arc is formed between electrode and crucible surface. Molten Silica (Quartz) is gradually reducted by carbonaceous material and finally forms liquid silicon.

The reaction course include:

Step 1: Molten Silica reaction with carbon forming silicon monoxide;

SiO2+C=SiO+CO

Step 2: Silicon monoxide further reaction with carbon to form solid silicon carbide;

SiO+2C=SiC+CO

Step 3: Silicon carbide reaction with molten silica to form liquid silicon and silicon monoxide which part of them recurs to step 2 and continuing the reaction circle.

SiO2+2SiC=3Si+2CO

OVERALL REACTION

SiO2+2C=Si+2CO

Liquid silicon is drained into a ladle via tap hole, after further removing impurity in ladle by blowing oxygen finally pouring into casting area.

Part of silicon monoxide, which escapes from continuing circle reaction with carbon, is combined with oxygen and exist in a form of gaseous SiO_2,?after filtration in filter this product is collected as byproduct.